RESUMO
PURPOSE: The purpose of this study was to evaluate the utility of the CT cholangiography by using helical CT with multiplanar reformation in patients with extrahepatic biliary obstruction. MATERIALS AND METHODS: Helical CT was performed in 36 patients of extrahepatic biliary obstruction confirmed by operation or invasive cholangiography(percutaneous transhepatic cholangiography or endoscopic retrograde cholagiopancreatography). The cause of obstructions were 18 benign diseases(11 common bile duct stones, four choledochal cysts, three pancreatitis) and 18 malignant diseases(seven common bile duct carcinomas, seven pancreatic head carcinomas, three ampullary carcinomas, one periampullary duodenal carcinoma). After helical scanning through the extrahepatic bile duct, retrospective reconstruction of the helical data was performed. And then, CT cholagiogram was obtained with multiplanar reformation. We evaluated the technical success rate and the accuracy in determinating the level and the cause of the obstruction. We compared findings of the CT cholangiogram with that of operation or invasive cholangiography. RESULTS: In 100%(36/36) of cases, CT cholangiography could be obtained successfully. The accuracy of the CT cholangiography in determinating the level of the obstruction was 100%(11 cases of suprapancreatic duct, 13 cases of intrapancreatic duct, 13 cases of infrapancreatic duct and ampulla), and the accuracy in determinating the cause of the obstruction was 91.7%(all cases of 18 benign diseases, and 15 cases of 18 malignant diseases). CONCLUSION: In evaluating the obstruction of extrahepatic bile ducts, the CT cholangiography by using helical CT with multiplanar reformation is an useful noninvasive method in determinating the level.and the cause of biliary obstruction and therefore could replace t~e invasive cholangiography.